Lakatos 1986.

Methods	A single‐centre, randomised, prospective controlled trial
Participants	204 outborn infants Inclusion criteria: premature infants, 751 to 2000 g BW, born between 1 January 1983 and 6 March 1984 Exclusion criteria: congenital abnormalities, death before 6 h of life
Interventions	Intervention group (n = 100) BW < 1500 g: D‐penicillamine intravenously started within 12 h after birth, 300 mg/kg/day (divided in 3 doses) x 3 days, then 50 mg/kg/day (in a single dose) until 2 weeks of age BW 1500‐2000 g: D‐penicillamine intravenously started within 12 h after birth, 300 mg/kg/day (divided in 3 doses) x 3 days; additional 50 mg/kg/day doses if they required oxygen beyond 3 days Control group (n = 104). No placebo was used in controls Once ROP developed after 6 weeks of age, D‐penicillamine 50 mg/kg/day was given to infants in the control group for 3 weeks
Outcomes	Death before discharge Any ROP in survivors
Notes	Follow‐up at 1 year of age for anthropometry and neurodevelopment presented in separate study (Vekerdy‐Lakatos 1987)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Authors do not provide the exact method of random sequence generation
Allocation concealment (selection bias)	Low risk	Sealed envelopes
Blinding (performance bias and detection bias) All outcomes	High risk	No blinding
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Group assignment not concealed from paediatricians, but ophthalmologists doing ROP examinations were masked to study group
Incomplete outcome data (attrition bias) All outcomes	Low risk	Outcomes of ROP reported on the majority of enrolled infants
Selective reporting (reporting bias)	Unclear risk	The study protocol was unavailable